This invention relates to a hand-held liquid, finger-operated pump and trigger sprayer of the type conventionally attachable to bottles containing liquids, such as detergents, soaps, lotions and insecticides. Many devices of this general type are well known in the prior art. One presently used trigger-type of these devices is disclosed in U.S. Pat. No. 3,061,202 issued to Tyler on Oct. 30, 1962. This patent shows a trigger-operated piston pump threaded onto a bottle. After priming, liquid is forced through a nozzle on the compression stroke of the piston and the cylinder refills on the intake stroke. Another presently used sprayer is disclosed in U.S. Pat. No. 3,749,290 issued to Miscallef on July 31, 1973. This patent discloses flexible tubular member which defines a pump chamber, the volume of the chamber being varied by distorting the tube. The present invention operates on the same general principles as the Tyler and Miscallef, but it is far less complex and expensive in that it uses a resilient bellows as the variable volume pump chamber, and all the required valving is molded integrally with an extension from the bellows structure.
Finger-operated pumps are also well known in the art; for example, see Malone, U.S. Pat. No. 3,396,874 and Corsetts, U.S. Pat. No. 323,757. Both of these patents show finger-operated pumps, but neither uses bellows piston having integral valving.
Stengle U.S. Pat. No. 3,409,184 also shows a bellows structure but it fails to teach the use of integral flaps for intake and discharge valving.
Other prior art known to the Applicants includes U.S. Pat. Nos. 788,863, 928,059, 2,112,548, 2,446,085, 2,878,974, 3,128,018, 3,146,920, 3,187,960, 3,237,571, 3,298,573, 3,396,874, 3,572,590 and 3,642,180. None of these is regarded as anticipatory.